DESCRIPTION (Applicant's Abstract): Long Term Goals: The high rates of recurrence following recovery from major depression have made it apparent that this is a chronic, disabling disorder. Patients who achieve remission continue to be at risk for a return of symptoms due to factors related to both the mechanisms underlying affective disorder (e.g., episode sensitization following from repeated experience with the disorder) and the lack of alternatives to maintenance pharmacotherapy (e.g., drug default rates for antidepressant maintenance medication range as high as 40%). The proposed research is intended to develop a psychotherapeutic treatment for depressed patients who have achieved clinical remission with pharmacotherapy, and are candidates for maintenance treatment. Attentional Control Training (ACT) is based on an information processing analysis of the nature of cognitive risk for depressive recurrence. This approach integrates cognitive behaviour therapy for depression with training in attentional reallocation in an effort to enable patients to identify negative cognitive processing earlier in the euthymic state, and to intervene with it more effectively. Method: This research plan has three stages. In the first stage, a treatment manual consistent with our theoretical model of the cognitive processes underlying recurrence in major depression will be developed. In the second stage, measures of therapist adherence to ACT and competency in ACT treatment delivery will be developed. Thirdly, treatment piloting will occur twice during the study period. Specific Aims: Six areas will be addressed; 1) development of a treatment manual to target cognitive mechanisms thought to underlie vulnerability to depressive recurrence in patients who are currently nonsymptomatic, 2) development of measures for judging treatment adherence and competence in delivering this approach, 3) assessment of whether this treatment can be taught to therapists in a fashion which produces competent performance, 4) development of measures of specific skills in attentional control, 5) assessment of whether the measured skills in attentional control change as a result of receiving ACT, 6) collection of feasibility data on ACT; including indices of acceptability to patients, patient retention, compliance and use of taught skills over time. Health Relatedness: In light of the continued risk for recurrence following recovery from unipolar depression, there is a need to augment standard acute intervention to reduce the risk for symptom/episode return. This study seeks to develop a non-pharmacological maintenance treatment for prevention of unipolar depressive recurrence along with measures of treatment adherence, competence and mechanisms of change.